Gemstone



FIG. 1 is a top plan view of a gemstone showing my new design;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a first side elevation view thereof; and,

FIG. 4 is a second side elevation view thereof, rotated 45° from the view of FIG. 3. 

The ornamental design for a gemstone, as shown and described. 